Zagster, a Cambridge-based bike-share company that wants to become the Zipcar for cyclists, is carving out a niche outside large cities. Unlike city-sponsored programs like Boston’s Hubway, with thousands of bikes, Zagster makes its money by leasing smaller numbers of bikes to companies and colleges, as well as towns and smaller cities. Early next week, the company will announce its latest innovation. Billed as a first in North America, Zagster will soon start outfitting its…